WowAce

This isn't class-specific. Several classes, and vehicles, use combo points.

Hm. oUF disables ComboFrame at the same time it does TargetFrame. Blizzard's fault for parenting ComboFrame to UIParent, I guess. Though RuneFrame has the same issue, but oUF doesn't disable it.

I wonder how hard it is to restore ComboFrame to its original state and use it...

Ugh, the default UI's implementation of this is a disaster, and uses this onupdate-based "fade" logic. (See UIFrameFade_OnUpdate and other functions.) Looks like for ComboPoints, I'm using the oUF CPoints element and some Animaions, not trying to salvage the default behavior!